Fusion systems and methods of assembly and use

Abstract

The fusion systems include a first fastener, a second fastener, and an elongate member with a first end and a second end. The first end being secured to the first fastener and the second end being secure to the second fastener. The method of assembling a fusion system including obtaining towers, fasteners, and an elongate member; coupling the fasteners to the towers; inserting ends of the elongate member into the fasteners; coupling locking caps to a screwdriver; and screwing the locking caps into heads of the fasteners to secure the ends of the elongate member to the fasteners. The methods of using the fusion systems including exposing a patient's vertebrae and obtaining the fusion system, inserting first and second fasteners into first and second vertebra, and coupling the first fastener and second fastener.

Having thus described the preferred embodiments, the invention is now claimed to be: 
     
       1. A screw, comprising:
 a head, comprising:
 a slot; 
 a body portion defining an interior surface and a top surface; 
 a base portion extending below the body portion defining a concave interior surface; and 
 at least one tab positioned on an exterior surface of the body portion and extending away from the exterior surface and from the top surface toward the base portion; 
 wherein the slot forms a first side surface and a second side surface in at least the body portion; and 
 wherein the at least one tab extends only a portion of a space between the first side surface and the second side surface of the slot and the at least one tab is positioned spaced apart from the first side surface and the second side surface of the slot; 
 
 a shaft; and 
 a neck coupling the head to the shaft. 
 
     
     
       2. The screw of  claim 1 , wherein the base portion includes one rod opening extending from an exterior surface into an internal portion of the screw. 
     
     
       3. The screw of  claim 1 , wherein the interior surfaces of the body portion and the base portion of the head cooperatively form a cavity. 
     
     
       4. The screw of  claim 3 , wherein the concave interior surface of the screw defines a first radius. 
     
     
       5. The screw of  claim 3 , wherein the slot extends through the body portion from the top surface thereof and through a portion of the base portion to the cavity. 
     
     
       6. The screw of  claim 4 , further comprising:
 a locking cap comprising a bottom surface with a concave first recess defined by a second radius, the locking cap threadably engaged with the body portion of the head within the cavity. 
 
     
     
       7. The screw of  claim 1 , wherein the slot is configured to provide for angulation of a rod within a cavity formed by interior surfaces of the body portion and the base portion along a first axial plane that is aligned with an axis between a bottom end surface and a top surface of the head with a range of 20 degrees to 40 degrees. 
     
     
       8. The screw of  claim 7 , wherein the slot is configured to provide for angulation of the rod within the cavity along a rotational plane that is normal with respect to the axis between opposing lateral sides of the slot of the head with the range of 10 degrees to 30 degrees. 
     
     
       9. The screw of  claim 1 , wherein the screw is elongated along a first axis, and wherein the body portion of the head is annular and extends continuously circumferentially about the first axis between opposing lateral sides of the slot, and wherein the body portion of the head extends circumferentially about the first axis between opposing lateral sides of the slot within a range of greater than 180 degrees and less than 345 degrees. 
     
     
       10. The screw of  claim 1 , wherein a bottom end surface of the slot is defined by the base portion of the head. 
     
     
       11. The screw of  claim 10 , wherein the screw is elongated along a first axis. 
     
     
       12. The screw of  claim 11 , wherein the body portion of the head is annular and extends continuously circumferentially about the first axis between opposing lateral sides of the slot. 
     
     
       13. The screw of  claim 12 , wherein the body portion of the head extends circumferentially about the first axis between opposing lateral sides of the slot within a range of greater than 180 degrees and less than 345 degrees. 
     
     
       14. The screw of  claim 1 , wherein the at least one tab is two tabs. 
     
     
       15. The screw of  claim 14 , wherein a first tab is positioned circumferentially offset from the first side surface of the slot, wherein a second tab is positioned circumferentially offset from the second side surface of the slot, and wherein the first tab is circumferentially spaced apart from the second tab. 
     
     
       16. A screwdriver, comprising:
 a handle portion; and 
 a shaft portion coupled to a central part of the handle portion, wherein the handle portion is perpendicular to the shaft portion, wherein the shaft portion of the screwdriver comprises:
 a shaft with a first end and a second end; 
 a screw member positioned at the second end for engaging a first opening of at least one fastener; and 
 a protrusion for engaging a second opening of at least one fastener; 
 wherein the screw member is positioned at a distal end of the shaft, and 
 
 wherein the protrusion extends away from a side surface of the shaft,
 wherein at least the shaft portion has a cannulated opening, and 
 wherein the cannulated opening of the shaft portion receives a guide wire that extends from a position near the second end of the shaft and into a slot in the handle portion to position an end of the guide wire in a body of the handle portion. 
 
 
     
     
       17. The screwdriver of  claim 16 , wherein the screw member is hexagonally shaped. 
     
     
       18. The screwdriver of  claim 16 , wherein the protrusion is rectangular shaped. 
     
     
       19. The screwdriver of  claim 16 , wherein the handle portion comprises:
 a body; and 
 an opening positioned intermediate a first end and a second end of the body, wherein the opening receives and couples to a first end of the shaft portion.